Honda HA-420 Serious Contender

The newest entrant to the competitive world of light jets has made its presence known through performance, efficiency and attention to detail.

An ancient axiom of aviation is that a company that sets out to design a brand-new airframe and wrap it around a brand-new engine design had better have a vast pool of money, expertise and patience or an excellent team of bankruptcy attorneys. The aircraft-manufacturing world is littered with the remains of companies and concepts that simply could not get through the astronomical combination of variables and issues that must be identified and subsequently solved when absolutely everything is new. With the financial backing of an automotive giant, Honda Aircraft pulled it off, although it took nearly 20 years.

Privately wondering whether Honda’s engine-over-the-wing concept was a marketing gimmick consistent with the T-tail of the 1970s, we approached reviewing the HondaJet with more than a little skepticism. After all, it is going head-to-head with some very capable jets manufactured by a company that’s been building jets for over 60 years (Cessna M2) and one that has the powerful resources of a government behind it (Embraer Phenom 100).

After spending time at Honda Aircraft’s massive (more than 600,000 square feet on 130 acres) facility on the Greensboro, North Carolina, airport, submerging ourselves in technical data on the airplane, flying it and getting all of our questions answered in detail, we came away of the opinion that the HondaJet HA-420 is an impressive aircraft. We also think that Honda Aircraft is in the aviation biz for the long run and the HA-420 is just the tip of the iceberg of products that will emerge from Honda Aircraft’s secretive facility.

Background

Following years of research, the basic design for the HondaJet was sketched out in 1997, a patent for the over-the-wing engine mount configuration was obtained in 2001 and first flight of a prototype took place in 2003. In 2006, Honda announced that it would “commercialize” the HondaJet and said deliveries were expected to begin in 2010.

By 2011 the conforming prototype had demonstrated a 420-knot max cruise speed and rate of climb of 3995 FPM. As the jet approached certification, Honda Aircraft established a network of service centers through the U.S. and Europe. Certification and delivery of the first HondaJet occurred in December 2015 (known icing certification came nine months later). As this is being written, 45 HondaJets have been delivered—15 in the first quarter of 2017—and we were told that the order book stood at 100 for the $4.8 million jet.

Concurrently Honda began developing a small turbofan engine. It then partnered with a company with extensive experience in certifying turbofans, GE Aviation, although GE had never certified one putting out just 2000 pounds of thrust. What eventually became the GE Honda HF120 was certified in 2013 at 2095 pounds of thrust (derated to 2050 for the HF420). The goal of engine design was lowest fuel burn, lowest weight and highest TBO.

TBO is currently 2500 hours, although it is expected to go to a targeted 5000 hours as operating experience is gained. Weighing less than 400 pounds, it has an impressive 5-to-1 thrust-to-weight ratio, a 2.9 bypass ratio and engine pressure ratio of 24—allowing higher internal temperatures and more efficiency than competitors, helping keep cruise fuel burn to what appears to be the lowest in the HA-420’s class while shoving the airframe along some 20 knots faster than its competitors.

The Basics

The HondaJet’s size is deceptive—at 42.65 feet long, it is almost exactly the same length as its direct competitors, the Cessna M2 and Embraer Phenom 100, yet the cabin is significantly larger (17.8 feet from the forward to aft pressure bulkhead) and it has cavernous aft baggage space (57 cubic feet). The club-seated passengers’ feet don’t overlap—unheard of in light jets, and apparently a big thing to buyers. The lengthy cabin and baggage area are a result of mounting the engines on the wings rather than on the aft fuselage.

Over-the-wing pylon engine mounts were used on a few jets in the 1970s. The design died out until Michimasa Fujino, designer of the HondaJet, explored the idea of creating a wing pylon that would allow the engines to be positioned well aft. Fine-tuning the pylons—from head on, they look like the arm and hand of a pitcher throwing a fast ball—through extensive wind tunnel testing resulted in a lower drag configuration than fuselage-mounted engines, reduced shock wave strength at higher Mach numbers and generated good stall characteristics—although it still requires a stick pusher.

Head on view shows engine pylons mounted on the outboard portion of the engine nacelles.

The small, heavily loaded wing has “bumps” or what look to be small, span-wise stall strips at the midpoint of the upper wing surface in front of the ailerons. We were told they help keep the airflow attached to the ailerons at high Mach numbers. The winglets have small triangle-shaped vortex generators on the upper leading edges for airflow control if a high side-slip is induced.

Loading

The HA-420 has aluminum wings and a composite fuselage—the composite allowing the complex curves needed to create the drag-reducing, “natural laminar flow” nose. Honda literature shows a basic empty weight (BEW) for the jet of 7203 pounds. The airplane we flew was some 200 pounds heavier, at 7400 pounds. With all of its 2850 pounds of fuel aboard, and a max ramp weight of 10,680 pounds, only 430 pounds of payload remains.

[IMGCAP(3)

Honda claims an NBAA IFR range with four occupants of 1223 NM. They may have publicized an unrealistically light empty weight that doesn’t match airplanes equipped as the customers desire—so the range number may be optimistic for the real world.

Nevertheless, on the other end of the scale—maximizing payload—the zero fuel weight (ZFW) is a whopping 8800 pounds. That makes for a payload of 1400 pounds and 1880 pounds of fuel—two-thirds of capacity—allowing a full-boat realistic NBAA range of 800 NM.

Rail under the belly fuel tank protects against tank breach in a gear-up landing.

The fuel system turns out to be what we expect in a modern jet—dead simple. Filling is through a single port in the tail. The four tanks are filled progressively—first the two wing tanks, then a belly tank and finally an aft-fuselage bladder tank. The fuel then gravity feeds to the wing tanks, which supply the respective engines via pumps.

While all fuel and lines are outside of the pressure vessel—good crashworthiness design, in our opinion—we look carefully at designs where fuel is carried in the fuselage. We’ve looked at a lot of post-crash fire data and have observed that there is virtually no increased risk from aft fuselage tanks, so we have no objection to the aft bladder in the HA-420. Further, when Cessna put fuel in the belly of the Citation III, it installed a set of fore-to-aft rails under the belly to protect the tank in gear-up landings and crashes. The design worked. We applaud that the HondaJet design includes a robust rail under the belly tank and opine that it will provide adequate protection for that tank.

At the max operating altitude of FL430 the 8-PSI max differential pressurization system generates a cabin altitude of 8000 feet.

Honda worked closely with Garmin to tailor and integrate the G3000 flight deck with the HA-420. We found the touchscreen and shallow menus intuitive. With Honda’s close ties with F1 racing, we were not surprised to find buttons and switches on the yoke that made it possible to scroll through and activate many of the G3000 features without letting go of the control wheel.

Flying It

Cockpit showing Garmin 3000 display.

The first impression when getting into the cabin of the HondaJet is that it’s bigger than expected. Once in the left seat, we were surprised to find that even being 6 feet 4 inches tall, we had plenty of leg and headroom—not a common experience. The seat and rudder pedals both adjust through a long range and should comfortably fit any size pilot.

The HondaJet does not have an APU; however, it does have a “ground cooling mode” in which one engine is operated in a manner that it only burns 90 pounds of fuel per hour while running the air conditioning compressor. The engines are full FADEC, so startup and operation is largely pushing a button or moving a power lever to command the system. Power setting on takeoff consists merely of pushing the power levers to the takeoff detent; on climbout they are pulled back slightly to the max continuous power detent and left until there is a reason to pull them further back.

The major shortcoming we identified with the HA-420 is that it’s not a short field machine. Its balanced field takeoff length at sea level on a standard day is 3990 feet. It will land in just over 3000 feet. While Honda says it can use 4000-foot runways, we think that 5000 feet of pavement is the minimum length for a home base to allow for days when the runway is wet or icy.

Where the HondaJet shines is once it gets off the runway—from what we can tell, it outperforms the competition. Its demonstrated climb rate at sea level on a standard day is 3995 FPM. In addition, the extensive system automation turns an engine power loss on takeoff into a non-event. We were prepared to firewall the rudder when Honda chief pilot Tim Frazier pulled one engine back, but the automatic rudder bias made the required input a matter of a few pounds of force.

At FL310 the jet settled down to a cruise at 420 KTAS—some 20 knots faster than its competition. At max operating altitude, FL430, the airplane cruises at 386 knots while burning a total of 600 pounds of fuel per hour, one of the most efficient jets we’ve come across.

Nose gear scissors can be disconnected to protect against damage when towing.

When it was time to descend, deployment of the tail-mounted speedbrakes caused no pitch change, only a slight rumble and substantial increase in the descent rate.

Maneuvering through steep turns, slow flight and around the traffic pattern was delightful. The controls are nicely harmonized with a solid transport feel, but effective enough that the airplane can be tossed around if the need arises. Due to the minimal dihedral and short landing gear, crosswind landings must be made with consideration for the potential of dragging a wingtip. The airplane is limited to no more than 20 knots of crosswind. Above 15 knots it is landed as is a jet with engines in pods beneath the wings: a crabbed approach that is kicked out during the flare. The AFM has specific crosswind landing procedures.

HA-420 Training: Flight Safety At The Factory

Honda Aircraft’s HA-420 HondaJet is a turbojet, so despite a gross takeoff weight of less than 12,500 pounds, a type rating is required. We were told that the target demographics—and cross section of actual buyers—split about fifty-fifty between corporate flight departments and owners who were not professional pilots but were going to fly their own jets.

While owner-flown jets have become increasingly common, the challenge of creating a training program that can take a classroom consisting of pro and amateur pilots from zero to the required ATP-level proficiency necessary to pass a type-rating checkride in a reasonable period of time hasn’t gotten any easier.

Honda Aircraft selected FlightSafety International to handle flight and maintenance training and specified that FSI set up its training center within Honda Aircraft’s Greensboro, North Carolina, facility.

The 14-day flight training curriculum mixes classroom and simulator time and is designed to take a commercial, instrument, multi-engine pilot with no jet time through a type rating. However, in looking at the program, we rapidly concluded that it’s not a one size fits all affair—it is tailored as needed to fit the student.

Honda Aircraft also teamed with insurers to set up a program for pilots to fly with newly type-rated owners for a period of time—seasoning, for lack of a better term—to help assure their smooth transition into comfortable, safe operation of their jets.

HondaJet training begins with classroom time. However, the classroom isn’t a dry lecture hall. The student is immediately introduced to “operational day flow,” ODF, which means they start using desktop simulators that mimic the HondaJet’s integrated Garmin G3000 avionics suite in the classroom. FSI’s HondaJet Training Center manager Bryan King, top photo, explained that the desktops have touchscreen controllers identical to the control display unit (CDU) of the flight management system in the jet. A mouse is used to move thrust levers and switches. The idea is to move right into flight scenarios, making things as real as possible.

Students next move into one of the graphical flight simulators, GFS, middle photo, with full-scale displays and touchscreens and, importantly, dynamic graphic system schematic displays at the top.

The system displays show what is going on as the pilot works through normal, abnormal and emergency operations of the various systems. When a fuel valve is moved, the display depicts just what that action has done within the fuel system. Students have 24-hour access to the GFS units.

Finally, the students move into the full-motion, Level D simulator, bottom photo. Before doing so, they spend some time with a pilot’s seat mounted on a pedestal so that they can clearly see each of the eight adjusting levers and switches so they don’t waste precious minutes fumbling to adjust their seat once in the sim. While that may be a small thing, it reflected what we observed to be an almost obsessive attention to detail throughout Honda Aircraft’s operations.

We found the Level D sim to be everything Level D sims normally are—a remarkably realistic duplication of flight operations with superb displays. Control response was close to the airplane itself, but as is normal with sims, slightly harder to fly than the real thing.

FlightSafety has been effectively training pilots of all skill and experience levels to fly jets single-pilot in complex environments. With the new operational day flow we think the training has gotten even better.

Conclusion

The quality of the HondaJet and size of its manufacturing facility indicate that the company has the capital to step into the aviation world beyond light jets and make an impact. It has thus far done so with an up and running customer service system and an airplane that outperforms the competition on a lower fuel burn. We think the HondaJet has attracted some buyers because of Honda’s reputation for quality in the automotive, motorcycle and small engine world and will continue to do so. We’re also quite curious as to what will come out of the massive facility next.